Multiple heat exchange coil



March 14, 1933. M E LE AL 7 1,901,090

MULTIPLE HEAT EXCHANGE COIL Filed July 16 1931 2 Sheets-Sheet l March 14, 1933. M. EULE ET AL I MULTIPLE HEAT EXCHANGE COIL Filed July 16, 1931 2 Sheets-Sheet 2 I Patented Mar; 14, 1933 Jlrelates to 'such a packet of tubing which 'diifers, however, from the arrangements airs ."rT ES rarest P T ENT Friar-1* mam new, or nnRLm-srAnnAu, AND Enron Animus, or BERLIN-ammunitauzas, enanamr, ASSIGNORS r0 smmnns-scnucxnnrwnnxn Axrmnensnu- SGHAIFT, 0E emmn-smmnnssrmr, GERMANY,

A CORPORATIGN OF GERMANY MULTIPLE HEAT EXCHANGE COIL I Application filed July 16, 1931, Serial No.'551,148, and in Germany Nov eniber30, 1929.

Our invention relates to multiple heat exchange coil as used in feed-water heaters and superheate of steam plants.

To facilitate the assemblage of the heating surfaces in heat exchangers, for example f ced-water heaters or superheaters, consisting of tubing or piping, the heating surfaces are mostly subdivided into separate packets or groups oftubing. The present invention known in the art by the fact that it consists of two or more tube lengths joined in parallel and which are helically wound in contrary directions into the shape of flat cylinders the lateralsurfaces of which are parallel to one another,the coils of tubes thus formed being inserted into :one another.

A packet of tubing of that kind-has cer a tain advantages compared with the ackets of tubing hitherto known. If only on ("tube length is employed and the flow area-of the packet of tubing has to be increased, a tube having a larger internal diameter must be used. Consequently, when larger fiow areas are required, a size of ipe must be used which s,'-bes1des,- the radius of bending of the tube increases with the size of the tube, the overall dimensionsv of a packet, made of a single tube length, also tube coils wound in contrary directions by inserting them into one another, two cases come into conslderation. .As long as lt 1s not intended to"insert the spirals, formed by the tubes and coiled in contrary directions, "so'farinto one another that-their return or end bends lie exactly incoaxial relation, no

obstacle is encountered in bringing the spirals into position. Otherwise it must betaken into account that owing to the tubes being coiled in contrary directions the longitudinal sides of the different tube spirals would intersect. If, in "order-to obtain a better util-- ization of the'available space, the coils wound clockwise and counter-clockwise are to be in- I dividual tube coils to be inserted into one another remains in this case an easymatter. The tubes are first wound into flat spirals, and

then all coil lengths on one side are pressed in further toward theimaginary center line drawn between thereturn bend centers of the coils, until the distance between the parallel sides of the coil is reduced by at least the diameter of the tubing used in the coils for the reason apparent from the detailed de-=' scription of the drawings. a

A packet of tubing made in the aforedescribed manner by inserting, for example, two coils wound in contrary directions into each other, is illustrated in the accompanying drawings.

Fig. 1 shows as a whole the arrangement of a superheater section 1 and of a feed-water heater section 2, both consisting of packets of tubing constructed in the one .or the other manner according to the invention.

Fig. 2 shows a section on the line 2-'-2 in Fig. 1. Q Fig. 3 shows how the tube spirals wound clockwise and counter-clockwise may be shaped in order to render-it possible for them to be inserted into each other far enough to place all return bends exactly into axial 'alineme'nt, as illustrated in Fig. 2.

Fig. 4 is a cross-sectionalview, on an enlarged seale,takenon the line 4-4 of Fig. 2 and represents a suitable manner of supporting and suspending the tubes bent as 'in Fig.3.'

Fig. 5 shows the other shape mentioned above for the packet of tubing in which the tube spirals are not placed into one another so far as to axially align the return bends.

Fig. 6 shows an arrangement for the suspension of tubes disposed as in Fig. and represents a section through 6-6 in Fig. 5, on an enlarged scale, and v Fig. 7 shows details of the tube suspension I illustrated in Fig.6 and is a sectional view taken on line 7 7.

From the diagrammatic representation in F ig. 3, the necessity will be plainly seen for making in each case the distance between the two parallel sides of the flattened coil smaller than the diameter of the return bends, if the two contrary wound spirals are to be placed so far intoone another that their return bends come ex'actly intdaxial alinement, i. e. that they can be mounted on a common arbor as shown in Fig. 3. In Figs. 1, 2 and 3, 3

is a counter clockwise-wound tube coil and 4: a clockwise-wound tube coil.

To secure the indiv dual wmdmgs 1n thelr positions relativeto one another, distancerings 5 are placed between the windings and a tubular member 6 is passed through each return bend. The tubular member 6 is supported by a plate or disk 7 resting on a nut 8 threaded onto a central suspension rod 9. At its top end the tubular member 6 is centered by rings 10 and 11. If the coils-are to be-so Wound that the tubes joined in parallel are always at the same distance from each otherthen the spirals can be placed into one another only as far as shown in Fig. 5. In that case the tubes can no more be suspended in the manner shown in Fig. 4, but specially formed carrying brackets 12 and 13 become necessary. These brackets are shown in Figs. 6 and 7. In Fig. 6'the path of each coil is indicated in dash-dot lines. The carry ing brackets here also rest upon a plate or disk 14 held by the suspension rod 16.

We claim as our invention: y l. A packet of tubing for heat exchangers or the like, consisting of a plurality of tube lengths, wound into similarly shaped independent helical coils, some running "clockwise and others counterclockwise all of said coilscoaxially disposed relatively to one anbeing other, each of said coils having the shape of a flattened cylinder, whose lateral surfaces constitute two parallelplanes spaced apart from one another, the turns of each coil being other,each-of said coils having the shape of a flattened cylinder, whose lateral surfaces constitute two parallel planes spaced apart from one another, a distance less than the return bend diameter by 'at least the tube diameter, the turns of each coil being inserted between the turns of an oppositely wound coil, sufiiciently far, to align all adjacent return bends into acommon axis, the number of spaced parallel planes in which the straight tube portions of the coils are located being equal to the total number of parallel vcoil sides contained in the packet.

3. A packet of tubing for heat exchangers or the like, consisting of a plurality of tube lengths, wound into. similarly shaped independent continuous coils, some running clockwise and others counterclockwiseyeach of said coils having the shape of a flattened cylinder, whose lateral surfaces constitute two parallel planes spaced apart from one another, the turns of each coil being inserted between the turns of an oppositely wound coil, the number of spaced parallel planes in which the straight tube portions of the coils are located being equal to thetotal number of parallel coil sides contained in the packet, and a spacing rack for said tube coils, consisting of two component elements, each arranged to space and support the tubes of adjacent sides of different coils, and a common suspension bar arranged between said elements and-having a carrier plate at its lower end, forming a common longitudinal support for saidelements.

In testimony whereof we afiix our'signa-' tures.

MARTIN EULE. -ERICH ANDERS.

inserted between the turns of an oppositely I and others counterclockwise all of said coils being coaxially disposed relatively to one an- 

